Estimation of flood loss functions by activity sectors in the Pamplona metropolitan area in Spain by using insurance flood direct damage data

Flood risk assessment studies require information about direct damages that depend on several variables, such as water depth, water velocity, flood duration, activity sector and type of building, among others. However, loss functions are usually simplified through flow depth-direct damage curves. Direct flood damages driven by a given flood event can be estimated directly from such loss functions by using either known or estimated water depths.

In his study, flow depth-direct damage curves are estimated for a set of activity sectors in the Pamplona metropolitan area located in the northern part of Spain, within the activities of the EIT Climate-KIC SAFERPLACES project. A dataset containing all flood direct damages in the Pamplona metropolitan area in the period 1996-2018 were supplied by the Spanish ‘Consorcio de Compensación de Seguros’ (CSC), benefiting from the fact that CSC is the insurance company that covers all damages produced by natural hazards in Spain. Flood direct damages are classified by activity sectors and postal codes. In addition, observed streamflow data at a set of gauging sites in the Ulzama and Arga rivers were supplied by both the Ebro River Basin Authority and the Regional Government of Navarre. A set of seven flood events with both streamflow and direct damage data available were selected. Flood hydrographs in the Arga River at Pamplona were obtained with a temporal resolution of 15 minutes. The Regional Government of Navarre supplied the real flood extensions for a set of flood events. With such real flood extensions, the two-dimensional hydrodynamic IBER model was calibrated. Flood extensions and water depths with a spatial resolution of 1 m were estimated with the calibrated hydrodynamic model for the seven flood events. Combining the dataset of direct damages with standard flow depth-direct damage curves and with water depths simulated by the hydrodynamic model, flood depth-damage curves were estimated by municipalities and postal codes. Such curves were obtained for activity sectors, considering residential, commercial and industrial assets.

Acknowledgments

This study was supported by the project SAFERPLACES funded by the EIT Climate-KIC. The authors also acknowledge the ‘Consorcio de Compensación de Seguros’ for providing the flood direct damage dataset and the Regional Government of Navarre for providing the real flood extensions for given flood events.